The invention relates to an implant for stabilizing vertebrae or bones. In particular, the invention relates to an implant for stabilizing an osteoporotic vertebral body.
A known method for the treatment of vertebral body fractures is the so called vertebroplasty. Bone cement of low viscosity is injected with high pressure directly into the fracture site of the vertebral body. There is a risk that a portion of the bone cement exits the vertebral body and flows into the surrounding area. This may cause discomfort or pain since the bone cement can press onto nerves or the spinal cord. Also, the vascular structure beyond the vertebral end plates can be damaged.
Another method for the treatment of vertebral body fractures is the so-called kyphoplasty. The method consists in first inserting a canula into the broken vertebral body. Then a balloon catheter is inserted into the vertebral body. The balloon is expanded by means of injecting a fluid under X-ray monitoring thereby creating a cavity defined by the balloon catheter volume. Thereafter, the fluid is discharged and the balloon is removed. In a next step bone cement is injected into the cavity. The bone cement can be a bone cement with high viscosity compared to that used in vertebroplasty. Although the risk of bone cement escaping into the surrounding is lower than in vertebroplasty, the risk is still not negligible. Also due to the size of the cavity the amount of bone cement used is substantial.
Both of these methods can also be applied to weak and partly collapsed osteoporotic vertebrae.
A problem which is common to vertebroplasty and kyphoplasty is that the vertebral bodies become completely stiffened which enhances the likelihood of a fracture of the neighbouring vertebral bodies due to overloading.
Based on the foregoing, there is a need to provide an implant for the stabilization of vertebrae or bones which overcomes the above mentioned problems.